Automated Peritoneal Dialysis (“APD”) is a natural evolution of Continuous Ambulatory Peritoneal Dialysis (“CAPD”), in which the patient introduces the entire contents of a dialysate solution bag into his/her peritoneum and allows the volume to dwell for three to six hours. After the dwell period, the fluid is drained using gravity. The above process is typically repeated three or four times each day as necessary. Working adults may perform an exchange at home before leaving for work, one at work during their lunch hour, one when the patient arrives home from work and one just before the patient goes to bed. Some school-aged patients follow a similar routine except they perform their mid-day exchange at school.
APD machines (sometimes called “cyclers”) perform sequential exchanges during the night when the patient is sleeping, making APD a more convenient therapy. Also, the treatment is carried out in the privacy of the patient's home, so that others do not have to know that the patient is on dialysis. It is no surprise that most patients would prefer APD over CAPD.
APD machines require set-up, typically involving the patient making multiple connections between dialysis supply bags and a disposable pumping cassette, which is then loaded into the APD machines. The connections include the removal of caps from the supply lines and the bags and then a physical connection of the lines to the bags. For older patients especially, the connections can be physically challenging. The patient also has to make sure that the lines are connected properly. Besides the supply lines, the disposable cassette can include other lines that do not connect to supply bags, such as a patient line, drain line and heater bag line. The patient has to make sure not to connect one of these lines to the bags.
Recently, auto-connection systems have been developed that connect the cassette and supply bags for the patient, saving the patient from having to perform these labor intensive steps. The auto-connection system has to perform the same steps that the patient had to perform manually, including the removal of caps from the tubes and ports, followed by the physical joining of the supply lines and ports.
When the caps have been removed, and before joining of the tubes and ports, it is possible for dialysis fluid to spill out of the supply lines. This is disadvantages for a number of reasons. First, spilling fluid is wasteful and deprives the patient of the full therapeutic benefit of the bagged solution. Second, liquid spilling into the APD machine can damage the machine. Peritoneal dialysis fluid in particular is sugary and sticky and difficult to clean from between cracks and seams of the machine.
A need accordingly exists for an auto-connection system that prevents fluid from spilling out of the supply tubing after the tubing caps have been removed for connection but before connection has taken place.